Hi, I have lost the powersupply of my E-MU proteus MPS. Can somebody help me for the electr. diagram/circuit of the powersupply? Or other info?On the photo of the original powersupply is listed only: Out CT 18V AC 1,5 amp.But there are going three wires in the synths. Two to the on/of switch and one directly to the bottom of the print (probably the 'ground'?).So I am wondering, what kind of AC transformer do I need? Probably a dual- trafo, but......2 x 18 V or 2 x 9 volt?Interesting: the Proteus FX uses a singel 9 V AC powersupply.Thanks for helping!Fred

Thanks for the warning MT, but I am not uncommon working with wiring, My only problem is - in the absence of the electr. diagram - that I like to know the AC voltage the trafo should deliver, read my question above. I wished somebody owns the powersupply and can measure the three outs of the trafo.

Hi Fred and welcome aboard.According to this pic from syntaur :It looks like it is a center tapped (CT) transformer that outputs 2 x 9V = 18VAC (9V-0V-9V). I think that the pinout is also printed on the top, but the pic quality doesnt help to take a readout. My guess is , according to the printed pinout, 9V (Left pin) - 0V (Top pin) - 9V (Right pin) Dont get madtheory wrong, power mains transformers can be lethal, if you don't know _exactly_ what you're doing.

commodorejohn wrote:I think it's actually 18V-0V-18V, but I'll try to remember to dig mine out this evening and check.

Thank you for your reply Yekuku and CommodoreJohn !! Yes I suppose also that it is a center tapped transformer. I saw the photo before.CommodoreJohn, I really hope you can find out what is the case 9-0-9 or 18-0-18? That will be of great help!!The top pin will be the 'zero'?And do you think the synth needs 2 x 1,5Amp or in total 1,5Amp?(pfff..... I've wrote several times to E-mu, but no reaction at all...)Fred

Have I got something wrong in the power supply? Could it be something in the MPS?

By zooming on the picture it looks like the pinout is correct, but i cant be 100% sure since I dont have the PSU in my hands.The PSU should output AC, but I guess you already know this since you are confirming that the regulators are working .The behavior that you describe means that the system does not initialize at start up , the main digital components (Eprom/CPU/DSP/RAM) are not working right. Are they getting 5Volts?No wonder why it was sold without a psu.

Its gone off again. I suspect this is an intermittent connection problem between the main board and the switch/display board. I should be able to fix that

As for the no sound issue, if i'm getting the test tones out of the diagnostic test then the DAC, Op amps etc should be ok (total guess), so it may be that the sounds are just missing and need to be copied from one bank to another?